--分析索引的构造关系
--查询索引的对象号
SQL> select object_id from dba_objects where object_name='IDX_T_DETAIL';
 
 OBJECT_ID
----------
     69559
 
--转储索引， 69559即为上述查询的信息
SQL> alter system set events 'immediate trace name treedump level 69559';
 
System altered
--trace文件如下：一个分支块，若干叶子块
branch: 0x2843803 42219523 (0: nrow: 21, level: 1) --level也可知分支块的为几级，nrow即为叶子块的个数,level为从此块到leaf的高度，故leaf无level
   leaf: 0x2843804 42219524 (-1: nrow: 485 rrow: 485) -- -1表明是同一层叶子块的第一个叶子块
   leaf: 0x2843805 42219525 (0: nrow: 479 rrow: 479)
   leaf: 0x2843806 42219526 (1: nrow: 479 rrow: 479)
   leaf: 0x2843807 42219527 (2: nrow: 479 rrow: 479)
   leaf: 0x2843808 42219528 (3: nrow: 479 rrow: 479)
   leaf: 0x2843809 42219529 (4: nrow: 479 rrow: 479)
   leaf: 0x284380a 42219530 (5: nrow: 479 rrow: 479)
   leaf: 0x284380b 42219531 (6: nrow: 479 rrow: 479)
   leaf: 0x284380c 42219532 (7: nrow: 479 rrow: 479)
   leaf: 0x284380d 42219533 (8: nrow: 479 rrow: 479)
   leaf: 0x284380e 42219534 (9: nrow: 479 rrow: 479)
   leaf: 0x284380f 42219535 (10: nrow: 479 rrow: 479)
   leaf: 0x2843811 42219537 (11: nrow: 479 rrow: 479)
   leaf: 0x2843812 42219538 (12: nrow: 479 rrow: 479)
   leaf: 0x2843813 42219539 (13: nrow: 479 rrow: 479)
   leaf: 0x2843814 42219540 (14: nrow: 479 rrow: 479)
   leaf: 0x2843815 42219541 (15: nrow: 479 rrow: 479)
   leaf: 0x2843816 42219542 (16: nrow: 479 rrow: 479)
   leaf: 0x2843817 42219543 (17: nrow: 479 rrow: 479)
   leaf: 0x2843818 42219544 (18: nrow: 479 rrow: 479)
   leaf: 0x2843819 42219545 (19: nrow: 414 rrow: 414)
  
--转储上述一个叶子块 leaf: 0x2843804 42219524 (-1: nrow: 485 rrow: 485)
---参数值即为叶子块的十进制地址
SQL> select dbms_utility.data_block_address_file(42219524) as 叶子块所在的文件号,
  2         dbms_utility.data_block_address_block(42219524) as 叶子块所在的数据块号
  3  from dual;
 
         叶子块所在的文件号           叶子块所在的数据块号
------------------ --------------------
                10               276484  

--转储下上述的叶子块，内部构成               
SQL> alter system dump datafile 10  block 276484;
 
System altered        

--trace内容如下，可知对应表记录数为485，与上述的叶子块 leaf: 0x2843804 42219524 (-1: nrow: 485 rrow: 485)一致
--说明此叶子块存储对应的表记录数为485
row#0[8024] flag: ------, lock: 0, len=12
col 0; len 2; (2):  c1 02
col 1; len 6; (6):  02 83 5c ec 00 00
row#1[8012] flag: ------, lock: 0, len=12
col 0; len 2; (2):  c1 03
col 1; len 6; (6):  02 83 5c ec 00 01
row#2[8000] flag: ------, lock: 0, len=12
col 0; len 2; (2):  c1 04
col 1; len 6; (6):  02 83 5c ec 00 02
row#3[7988] flag: ------, lock: 0, len=12
col 0; len 2; (2):  c1 05
col 1; len 6; (6):  02 83 5c ec 00 03
中间内容从略
row#484[1834] flag: ------, lock: 0, len=13
col 0; len 3; (3):  c2 05 56
col 1; len 6; (6):  02 83 5c ec 01 e4
----- end of leaf block dump -----
End dump data blocks tsn: 8 file#: 10 minblk 276484 maxblk 276484   

--也可把treedump命令用于oradebug之中，好处，直接看到生成的trace文件所在路径及名称
SQL> conn sys/system as sysdba
Connected.
SQL> oradebug setmypid
Statement processed.
SQL> alter session set events 'immediate trace name treedump level 69559';

Session altered.

SQL> oradebug tracefile_name
d:\oracle11g_64bit\diag\rdbms\second\second\trace\second_ora_4444.trc